1. Field of the Invention
The present invention relates to a method for preparing trimer of .alpha.-methyl styrene or derivatives thereof.
2. Description of the Prior Art
There have been known many methods for preparing an oligomer of .alpha.-methyl styrene or derivatives thereof, including a method using silver fuluoroborate (Japanese Patent Unexamined Application, hereinafter referred to as "J.P.KOKAI" No. Sho 50-157343), a method using an alkyl aluminum, a method using a salt of ultra strong acid (Japanese Patent Publication for Opposition Purpose, hereinafter referred to as "J.P.KOKOKU" No. Sho 57-10851), a method for treating .alpha.-methyl styrene in the presence of sulfonic acid type cation exchange resin under a given temperature (J.P.KOKOKU Hei 4-15771), a method for reacting .alpha.-methyl styrene with heteropoly acid in solid-liquid phase heterogeneous system in the absence of a solvent (J.P.KOKAI Hei 8-12601), a method using an oxygen-containing compound such as water, dihydric alcohol or ether as a reaction adjusting agent in the presence of a solid acid catalyst such as activated clay (J.P.KOKOKU Hei 8-23029).
Polymer Journal, vol. 13, No. 10, p. 947-953 (1981) discloses a method for preparing dimer and trimer of .alpha.-methyl styrene by cation polymerization of .alpha.-methyl styrene in the presence of binary metal oxide such as Al.sub.2 O.sub.3 --TiO.sub.2.